diff --git a/framework/CHANGELOG.md b/framework/CHANGELOG.md
index baa9db49f7..db13375e27 100644
--- a/framework/CHANGELOG.md
+++ b/framework/CHANGELOG.md
@@ -5,6 +5,7 @@ Yii Framework 2 Change Log
 ------------------------
 
 - Bug #13920: Fixed erroneous validation for specific cases (tim-fischer-maschinensucher)
+- Bug #19911: Resolved inconsistency in `ActiveRecord::getAttributeLabel()` with regard of overriding in primary model labels for attributes of related model in favor of allowing such overriding for all levels of relation nesting (PowerGamer1)
 - Bug #19872: Fixed the definition of dirty attributes in AR properties for a non-associative array in case of changing the order of elements (eegusakov)
 - Bug #19899: Fixed `GridView` in some cases calling `Model::generateAttributeLabel()` to generate label values that are never used (PowerGamer1)
 - Bug #9899: Fix caching a MSSQL query with BLOB data type (terabytesoftw)
@@ -17,6 +18,7 @@ Yii Framework 2 Change Log
 - Enh #19884: Added support Enums in Query Builder (sk1t0n)
 - Bug #19908: Fix associative array cell content rendering in Table widget (rhertogh)
 - Bug #19906: Fixed multiline strings in the `\yii\console\widgets\Table` widget (rhertogh)
+- Bug #19924: Fix `yii\i18n\Formatter` to not throw error `Unknown named parameter` under PHP 8 (arollmann)
 - Bug #19914: Fixed `ArrayHelper::keyExists()` and  `::remove()` functions when the key is a float and the value is `null` (rhertogh)
 - Enh #19920: Broadened the accepted type of `Cookie::$expire` from `int` to `int|string|\DateTimeInterface|null` (rhertogh)
 
diff --git a/framework/UPGRADE.md b/framework/UPGRADE.md
index 7d2ca03eb9..3a9569a982 100644
--- a/framework/UPGRADE.md
+++ b/framework/UPGRADE.md
@@ -100,6 +100,11 @@ Upgrade from Yii 2.0.45
   2.0.45 behavior, [introduce your own method](https://github.com/yiisoft/yii2/pull/19495/files).
 * `yii\log\FileTarget::$rotateByCopy` is now deprecated and setting it to `false` has no effect since rotating of 
   the files is done only by copy.
+* `yii\validators\UniqueValidator` and `yii\validators\ExistValidator`, when used on multiple attributes, now only
+  generate an error on a single attribute. Previously, they would report a separate error on each attribute.
+  Old behavior can be achieved by setting `'skipOnError' => false`, but this might have undesired side effects with
+  additional validators on one of the target attributes.
+  See [issue #19407](https://github.com/yiisoft/yii2/issues/19407)
 
 Upgrade from Yii 2.0.44
 -----------------------
diff --git a/framework/db/BaseActiveRecord.php b/framework/db/BaseActiveRecord.php
index 60f621eb44..9b00cb430f 100644
--- a/framework/db/BaseActiveRecord.php
+++ b/framework/db/BaseActiveRecord.php
@@ -1610,40 +1610,46 @@ abstract class BaseActiveRecord extends Model implements ActiveRecordInterface
 
     /**
      * Returns the text label for the specified attribute.
-     * If the attribute looks like `relatedModel.attribute`, then the attribute will be received from the related model.
+     * The attribute may be specified in a dot format to retrieve the label from related model or allow this model to override the label defined in related model.
+     * For example, if the attribute is specified as 'relatedModel1.relatedModel2.attr' the function will return the first label definition it can find
+     * in the following order:
+     * - the label for 'relatedModel1.relatedModel2.attr' defined in [[attributeLabels()]] of this model;
+     * - the label for 'relatedModel2.attr' defined in related model represented by relation 'relatedModel1' of this model;
+     * - the label for 'attr' defined in related model represented by relation 'relatedModel2' of relation 'relatedModel1'.
+     * If no label definition was found then the value of $this->generateAttributeLabel('relatedModel1.relatedModel2.attr') will be returned.
      * @param string $attribute the attribute name
      * @return string the attribute label
-     * @see generateAttributeLabel()
      * @see attributeLabels()
+     * @see generateAttributeLabel()
      */
     public function getAttributeLabel($attribute)
     {
-        $labels = $this->attributeLabels();
-        if (isset($labels[$attribute])) {
-            return $labels[$attribute];
-        } elseif (strpos($attribute, '.')) {
-            $attributeParts = explode('.', $attribute);
-            $neededAttribute = array_pop($attributeParts);
-
-            $relatedModel = $this;
-            foreach ($attributeParts as $relationName) {
-                if ($relatedModel->isRelationPopulated($relationName) && $relatedModel->$relationName instanceof self) {
-                    $relatedModel = $relatedModel->$relationName;
-                } else {
-                    try {
-                        $relation = $relatedModel->getRelation($relationName);
-                    } catch (InvalidParamException $e) {
-                        return $this->generateAttributeLabel($attribute);
-                    }
-                    /* @var $modelClass ActiveRecordInterface */
-                    $modelClass = $relation->modelClass;
-                    $relatedModel = $modelClass::instance();
-                }
+        $model = $this;
+        $modelAttribute = $attribute;
+        for (;;) {
+            $labels = $model->attributeLabels();
+            if (isset($labels[$modelAttribute])) {
+                return $labels[$modelAttribute];
             }
 
-            $labels = $relatedModel->attributeLabels();
-            if (isset($labels[$neededAttribute])) {
-                return $labels[$neededAttribute];
+            $parts = explode('.', $modelAttribute, 2);
+            if (count($parts) < 2) {
+                break;
+            }
+
+            list ($relationName, $modelAttribute) = $parts;
+
+            if ($model->isRelationPopulated($relationName) && $model->$relationName instanceof self) {
+                $model = $model->$relationName;
+            } else {
+                try {
+                    $relation = $model->getRelation($relationName);
+                } catch (InvalidArgumentException $e) {
+                    break;
+                }
+                /* @var $modelClass ActiveRecordInterface */
+                $modelClass = $relation->modelClass;
+                $model = $modelClass::instance();
             }
         }
 
diff --git a/framework/i18n/Formatter.php b/framework/i18n/Formatter.php
index 3236a433be..001b81bfa9 100644
--- a/framework/i18n/Formatter.php
+++ b/framework/i18n/Formatter.php
@@ -460,7 +460,7 @@ class Formatter extends Component
         }
         $method = 'as' . $format;
         if ($this->hasMethod($method)) {
-            return call_user_func_array([$this, $method], $params);
+            return call_user_func_array([$this, $method], array_values($params));
         }
 
         throw new InvalidArgumentException("Unknown format type: $format");
diff --git a/tests/framework/db/ActiveRecordTest.php b/tests/framework/db/ActiveRecordTest.php
index f1370f4728..b74803b94d 100644
--- a/tests/framework/db/ActiveRecordTest.php
+++ b/tests/framework/db/ActiveRecordTest.php
@@ -2192,4 +2192,87 @@ abstract class ActiveRecordTest extends DatabaseTestCase
         $this->assertNotNull($order->virtualCustomer);
     }
 
+    public function labelTestModelProvider()
+    {
+        $data = [];
+
+        // Model 2 and 3 are represented by objects.
+        $model1 = new LabelTestModel1();
+        $model2 = new LabelTestModel2();
+        $model3 = new LabelTestModel3();
+        $model2->populateRelation('model3', $model3);
+        $model1->populateRelation('model2', $model2);
+        $data[] = [$model1];
+
+        // Model 2 and 3 are represented by arrays instead of objects.
+        $model1 = new LabelTestModel1();
+        $model2 = ['model3' => []];
+        $model1->populateRelation('model2', $model2);
+        $data[] = [$model1];
+
+        return $data;
+    }
+
+    /**
+     * @dataProvider labelTestModelProvider
+     * @param \yii\db\ActiveRecord $model
+     */
+    public function testGetAttributeLabel($model)
+    {
+        $this->assertEquals('model3.attr1 from model2', $model->getAttributeLabel('model2.model3.attr1'));
+        $this->assertEquals('attr2 from model3', $model->getAttributeLabel('model2.model3.attr2'));
+        $this->assertEquals('model3.attr3 from model2', $model->getAttributeLabel('model2.model3.attr3'));
+        $attr = 'model2.doesNotExist.attr1';
+        $this->assertEquals($model->generateAttributeLabel($attr), $model->getAttributeLabel($attr));
+    }
+}
+
+class LabelTestModel1 extends \yii\db\ActiveRecord
+{
+    public function attributes()
+    {
+        return [];
+    }
+
+    public function getModel2()
+    {
+        return $this->hasOne(LabelTestModel2::className(), []);
+    }
+}
+
+class LabelTestModel2 extends \yii\db\ActiveRecord
+{
+    public function attributes()
+    {
+        return [];
+    }
+
+    public function getModel3()
+    {
+        return $this->hasOne(LabelTestModel3::className(), []);
+    }
+
+    public function attributeLabels()
+    {
+        return [
+            'model3.attr1' => 'model3.attr1 from model2', // Override label defined in model3.
+            'model3.attr3' => 'model3.attr3 from model2', // Define label not defined in model3.
+        ];
+    }
+}
+
+class LabelTestModel3 extends \yii\db\ActiveRecord
+{
+    public function attributes()
+    {
+        return ['attr1', 'attr2', 'attr3'];
+    }
+
+    public function attributeLabels()
+    {
+        return [
+            'attr1' => 'attr1 from model3',
+            'attr2' => 'attr2 from model3',
+        ];
+    }
 }